Meaning of Idiom 'Rub Salt in (or into) the Wound'

To rub salt in someone's wound is to make a bad or painful situation worse, such as by pointing out a person's mistakes or shortcomings, teasing, or reminding them of how bad a situation is. When someone rubs salt into your wound, they make you feel worse than you did before. 1,2

Usage

"It was bad enough getting fired, you don't have to rub salt in the wound by telling me how bad I screwed up."

"After Sue missed the winning goal, her teammates rubbed salt in the wound by making fun of her."

Origin

Used since at least the mid-1800's.

Although rubbing salt into wounds, such as those caused by flogging, has at times been used as a cruel punishment, the ancient Egyptians, Romans, and Greeks all used salt on wounds for its supposed medicinal value. Often, salt was mixed with honey and used as an ointment. Salt was thought to prevent infection and to dry out the wound. Salt, or salt water, was often used as an antiseptic aboard ship, as well. The intense stinging pain this caused gave rise to the expression. 3,1